Sear-controlling mechanism for firearms



Nov. 19, 1957 0.0. SUNDERLAND 2,813,362

SEAR-CONTROLLING MECHANISM FOR FIREARMS Filed June 27, 1955 2 Sheets-Sheet 1 IN VENTOR Q WWF ATTORNEYS Nov. 19, 1957 Q O SUNDERLAND 2,313,362

SEAR-CONTROLLING MECHANISM FOR FIREARMS Filed June 27, 1955 2 Sheets-Sheet 2 IN VENTOR may a M4 444 7 ATTORNEYS SEAR-CGNTROLLING MECHANISM FOR FIREARMS ()swaitl 0. Sunderland, Fairfield, Conn.

Application .iune 27, 1955, Serial No. 518,164

Claims. (Cl. 42-69) This invention relates to firearms and more particulady to the sear-controlling mechanism for a firearm such as a pistol or rifle, for example.

As illustrated the invention is applied to a firearm wherein a sear is provided to engage the striker and hold it in cocked position. In firearms employing such a structure, it is, of course, desirable that the sear be positively held in locking engagement with the firing pin so that the firearm will not be accidentally discharged due to jar, shock or other causes. For example, in firearms wherein a slide or bolt is provided which moves rearwardly to permit the insertion of a cartridge into the chamber, it sometimes occurs that the jaw occasioned by the closing of the slide or bolt might effect release of the sear and, therefore, discharge of the firearm. It is contemplated by the present invention to prevent such an occurrence.

it is also desirable in firearms to be able to adjust the trigger pull by a fine adjustment so that any desired light or heavy pull will be necessary to release the sear.

In many constructions the sear is engaged directly by a part of the trigger or in some instances by a sear bar -or other member moved by the trigger to effect movement .of the sear to releasing position. In the present instance there is provided a sear-release lever which is operated by the trigger. This lever is of such a form that a portion of it stands below a part of the sear and blocks the sear against movement from the operative position in engagement with the striker. This sear-release lever is pivoted on a vertical axis so that it is permitted a lateral movement about its pivot or a movement in a plane at right angles to that in which the sear moves. Therefore, it can be positioned to lie in the path of a portion of the sear and block its movement while at the same time the movement of the sear-release lever is in such a direction that it will not be affected by shock or jar in a longitudinal direction such as might be occasioned by the closing of the bolt or slide. Also when the sear-release lever moves laterally as in the present case, the trigger pull may be very finely adjusted by convenient mechanism.

One object of the invention is to provide new and improved mechanism for controlling the sear of .a firearm.

A further object of the invention is ,to provide a seatrelease lever for the sear of a firearm, which release lever will be pivoted to move in a plane transverse to that of the movement of the sear.

Still another object of the invention is to provide a sear-controlling mechanism for a firearm wherein the sear moves about a horizontal axis and a sear-release lever is provided pivoted upon a vertical .axis, the sear- .release lever having a portion standing in the path ,of the portion of the sear to block movement of the latter, and the sear-release lever being moved by the trigger.

To these and other ends the invention consists .in the novel features and combinations of parts to be hereinafter described and claimed.

In the accompanying drawings:

Patented Nov. 19, 1957 Fig. 1 is a sectional view of the rear portion of a firearm, herein shown as a pistol, embodying my invention, and showing the parts in cocked position;

Fig. 2 is a top plan view of the frame of the pistol with the barrel and slide removed, showing the interior mechanism;

Fig. 3 is a view similar to Fig. 1 showing the parts in position assumed when the gun is fired;

Fig. 4 is a sectional view similar to Fig. 1, showing 'the parts in the positions occupied when the slide has been moved rearwardly to a position just short of its full recoil position;

Fig. 5 is a crosssectional view similar to Fig. l, showing a modified form of my invention;

Fig. 6 is a transverse sectional view on line 6-6 of Fig. 5; and

Fig. 7 is a detail perspective view of the sear mechanism employed in the modification of my invention shown in Figs. 1 to 4.

To illustrate a preferred embodiment of my invention I have shown in the drawings a firearm comprising a frame it to which is secured a barrel 11 by any suitable means such as the screw 12. Reciprocably mounted upon the frame is the usual slide 13, this slide being of hollow form, and the rear end thereof being closed by a block 14 secured to the frame by the screw 15.

Within the hollow slide 13 the striker 16 is reciprocably mounted and is provided on its front end with a firing pin 17 adapted to engage a cartridge in the chamber 18 through the opening 19 in the front of the slide. Also within the slide is the spring 20 which reacts upon the slide at its forward end and upon the block 14 at its rear end to hold the slide in its forward or battery position. A second spring 21, which lies within the spring 20, acts upon a shoulder 22 adjacent the forward end of the striker so as to normally urge the striker forwardly toward firing position.

The striker is provided with a recess 23 having at its rear end a shoulder 24 adapted to be engaged by a shoulder 25 upon a sear 26, this sear being pivoted to the frame at 27. As shown in Fig. l the sear is engaged with the striker and holds it in cocked position, the slide 13 being in its forward position.

The sear is provided with a tail portion 28 which is engaged by the striker when the slide is retracted, as shown in Fig. 4, so as to swing the sear about its pivot into the position shown in Fig. 1 in which it engages the striker. A spring 29 mounted in a recess 30 in the frame acts against the tail portion 28 of the scar and normally urges the sear in a direction to release its engagement with the striker. This spring at its lower end acts against a pin detent 31, the lower beveled end of which is designed to engage in one of the other of two recesses 32 (only one-of which is shown) in a transversely movable safety slide 33 mounted in the frame 10.

This slide is provided with a cut-out .or cut-away portion 34 adapted when the safety slide is in inoperative position to receive a rearwardly extending arm 35 on the lower end of the sear. It will be apparent that with this construction, when the slide v3?) is in the position shown in Figs. 1 and 2, the sear may be moved to position to release the striker and fire the gun, the arm 35 on the sear entering the cut-out 34 of the slide. However, when the safety slide is moved laterally with respect to the frame, the arm 3'5 engages a portion of the full diameter of the safety slide and prevents the release of the sear. It may also be noted that the sear spring 29 serves the double function of urging the sear to the position shown in Fig. ,3 and also releasably holding the safety slide in position to which it is moved.

The sear 28 isalso providedwith a-forwardly extending lug 36, this big being adapted to he engaged by the rear end 37 of a longitudinally extending arm 38 of a sear-release lever of bell-crank form pivoted to the frame by the pin 39 on a vertical axis so that the arm 38 swings laterally to move the rear end 37 to and from a position below the lug 36. The other arm 40 of the searrelease lever extends laterally from the pivot 39 and is engaged and actuated by an upwardly projecting lug 41 on a sear bar 42 slidably mounted in a recess 43 on the frame. The sear bar is pivoted at its forward end, as shown at .4, to the trigger 45 pivoted at 46 to the frame. A stop screw 47 may be provided in the trigger guard 48 to limit movement of the trigger.

With this construction it will be seen that when the parts are in position shown in Figs. 1 and 2, the lug 41 is in contact with the arm 40 of the sear-release lever, and the rear end 37 of this lever stands below the lug 36 on the sear. When the trigger is pulled rearwardly or in a counterclockwise direction about its pivot 46, the sear bar is moved forwardly, thus moving the sear-release lever in a counterclockwise direction, as shown in Fig. 2, about its pivot 39 and moving the rear end 37 of this lever from below the lug 36. This releases the sear so that it is moved to releasing position by the action of the forward movement of the striker due to the force exerted thereon by the spring 21. Also the spring 2% serves to urge the striker to releasing position.

The operative position of the sear-release lever may be adjusted by means of the screw 50 threaded into the frame and engaging the sear-release lever at its inner end. Adjustment of this screw will, of course, determine the area of the sear which is engaged by the release lever and, therefore, adjust the trigger pull. Also the sear-release lever is normally urged to its operative or engaging position by a compression spring 52 mounted in the frame. The force of this spring may be adjusted by a screw 53 which may be locked in any desired adjusted position by the screw 54 (Fig. 4), thus furnishing a very fine adjustment for the force necessary to move the searrelease lever to disengaging position.

It may also be noted that the upper edge of the lug 36 of the sear is beveled at one side, as shown at 55, so that when the sear is in the position shown in Fig. 3 and the rear end 37 of the release lever lies above the lug 36, the sear may be moved to the position shown in Fig. 1 and the beveled edge 55 of the sear will cam the searrelease lever out of its path so that when the sear reaches the position shown in Fig. l, the spring 52 may move the sear-release lever to its operative position.

The sear bar is provided with an upwardly projecting cam portion 57 which, when the slide is in its forward position, lies in a cut-away portion 58 of the slide but which is engaged by the shoulder 59 at the forward end of this cut-away portion to cam the sear bar downwardly when the slide is retracted, as shown in Fig. 4.

In Fig. 3 of the drawing the parts are shown in the position occupied when the trigger has been pulled and the striker has engaged and discharged the cartridge. When the slide is driven rearwardly by the recoil (it is understood that my improvement may be applied to an automatic or semi-automatic firearm) as shown in Fig. 4, the rear portion of the striker engages the tail portion 28 of the sear and moves the sear shoulder 25 upwardly against the tension of the spring 29 to a position to engage forwardly of the shoulder 24. At this time the slide has engaged the cam portion 57 on the sear bar and moved the sear bar downwardly out of the path of the sear-release lever so as to permit the spring 52 to return th's lever to the position shown in Fig. 2. If this occurs before the upward movement of t e sear, the sear-release lever will be cammed out of the path of the sear by the beveled portion 55 on the lug 36.

It will be understood that the slide continues its rearward movement for a short distance beyond that shown in Fig. 4-, and upon this continuing movement the sear 7 is moved to the position shown in Fig. l, and the rear end of the sear bar lies below the lug 36 on the sear.

The slide will then be moved forwardly by the spring 20 to the position shown in Fig. 1, the sear holding the striker in cocked position as shown in that figure. The cam portion 57 of the sear bar has now been released by the lower portion of the slide so that the part 41 of the sear bar again engages the laterally projecting extending arm 40 of the sear-release lever. This upward movement of the sear bar is effected by the torsion spring 60 (Fig. 2) which also serves as the trigger spring to move the trigger forwardly about its pivot 46, this spring acting upon the trigger and sear bar in a manner tending to increase the angle between them.

The parts are now in the cocked position shown in Fig. 1. Upon a pull rearwardly on the trigger, the searrelease lever is moved in a direction to remove the rear end 37 from below the lug 36 of the sear and release the striker so that it can be driven forward by its spring 21 to the position shown in Fig. 3 where it engages and discharges the cartridge.

A somewhat modified form of my invention is shown in Figs. 5 and 6, this modification differing from that just described principally in the construction of the scar and the safety mechanism. The parts which are the same as those shown in Figs. 1 to 4 are given the same reference numerals and will need no additional description.

In this form of my invention the rear end of the striker is extended into an opening in the block 14 as shown at 16*, so that the striker is thereby guided in its reciprocatory movement. The sear is of a different form from that previously described and is pivoted to the frame at 66 and provided with a lug 67 engaging the shoulder 24 on the striker. The sear is provided with a forwardly extending lug 68 similar to the lug 36 previously described and serving the same function in that this lug is adapted to lie above the rear end of the arm 38 of the sear-release lever and be controlled thereby. The operation of the parts is the same as that described in connection with the modification of my invention shown in Figs. 1 to 4.

In this instance the sear 65 is urged to its operative position shown in Fig. 5 by the spring 69, which spring acts against a cup-shaped member 70 slidably mounted in the frame, which in turn engages the lower surface of the sear to urge it to its operative or striker-engaging position. It may be noted that this is a direction opposite to that in which the sear 26 is moved by its spring. The spring 69 at its lower end engages against a plunger or detent 71 and forces this plunger into one or the other of two recesses 72 and 72 in a transversely slidable safety element 73 having a cut-out or cut-away portion 74 to receive the lower end of the member 70. At one side of the recess or cut-away portion 74 is provided a shoulder 75 adapted to engage the lower end of the member 70 when the safety slide 73 is moved to the left from the position shown in Fig. 6.

When the parts are in the position shown in Figs. 5 and 6, the trigger may be pulled to move the sear-release lever laterally and release the sear 65. The sear is then moved in a counterclockwise direction about its pivot 66 by the forward movement of the striker. This moves the member 70 downwardly into the recess 74 which is permitted when the parts are in the position shown in Fig. 6. It will be understood, however, that if the safety slide is moved to the left so that the plunger or detent 71 engages in the recess 72 the element 70 may not be moved downwardly against the tension of the spring 69 as it will be prevented from such movement by the shoulder 75 so that when the safety is in that position, the gun cannot be fired as the sear cannot be released.

It will also be noted that while the spring 69 urges the sear in the opposite direction to that shown in Figs. 1

to 4, it serves both as a spring for the safety detent and as a spring for the sear in that it acts to move the sear to its operative position to engage the striker and also acts against the detent or plunger 71 to hold the safety mechanism in the position to which it is adjusted.

It may be noted that, as shown in Fig. 3, the spring 29 holds the sear in releasing position when the striker is in its forward position so that the striker may be moved rearwardly with the slide upon the firing of the gun without the rear end of the striker fouling the lug 25. In the form of my invention shown in Figs. and 6, however, the rear end 16 of the striker is in engagement with the lug 67 of the sear even when the striker is in its forward position so that this engagement holds the sear in a downward position out of the path of the striker.

It may be noted that the arm 35 on the sear is provided with a beveled portion 35 shown in Fig. 7. When the safety slide 33 is moved to its safety position, the portion of the slide adjacent the cut-away portion 34 will engage the beveled area 35 and cam this portion of the sear forwardly or in a clockwise direction about its pivot 27, thus raising the lug 36 from engagement with the end 37 of the sear-release lever. Thus the sear is raised slightly above the position in which it is locked by the sear-release lever so there will be no danger of the striker being released by the sear even though the sear-release lever may be moved to disengaging position.

The same result is achieved with the construction shown in Figs. 5 and 6, and it will be noted that, as shown in the modification described in these figures, the shoulder 75 is slightly beveled at its inner end and when the slide 73 is moved to the left, as shown in Fig. 6, the cup-shaped member 70 will be cammed upwardly, as shown in this figure, thus raising the forward end of the scar and raising the lug 68 above the rear end 37 of the sear-release lever.

While I have shown and described some preferred embodiments of my invention, it will be understood that it is not to be limited to all of the details shown, but is capable of modification and variation within the spirit of the invention and within the scope of the claims.

What I claim is:

1. A firearm comprising a frame, a striker reciprocably mounted thereon, a sear pivotally mounted on the frame and adapted to engage the striker to hold it in cocked position, a sear release lever pivotally mounted on the frame on a vertical axis for lateral swinging movement, said lever having a part adapted to engage the sear to hold it in striker-engaging position, and a trigger-actuated means engaging said lever to move it to position to disengage said sear.

2. A firearm comprising a frame, a striker reciprocably mounted thereon, a sear pivotally mounted on the frame and adapted to engage the striker to hold it in cocked position, a sear release lever pivotally mounted on the frame on a vertical axis for lateral swinging movement, said lever being disposed forwardly of the sear and having a part adjacent the rear end thereof adapted to lie below a part of the sear and hold it in striker-engaging position, and trigger-actuated means to move said lever about its pivot to move the rear end thereof to position to disengage the sear and permit movement of the sear to position to release the striker.

3. A firearm comprising a frame, a striker reciprocably mounted thereon, a sear pivotally mounted on the frame and adapted to engage the striker to hold it in cocked position, a sear release lever pivotally mounted on the frame on a vertical axis for lateral swinging movement, said lever having a part adapted to engage the sear to hold it in striker-engaging position, a trigger-actuated means engaging said lever to move it to position to dis engage said sear, and spring means urging said searrelease lever toward sear-engaging position.

4. A firearm comprising a frame, a striker reciprocably mounted thereon, a sear pivotally mounted on the frame and adapted to engage the striker to hold it in cocked position, a sear lever pivotally mounted on the frame on a vertical axis for lateral swinging movement, said lever having a part adapted to engage the sear to hold it in striker-engaging position, a trigger-actuated means engaging said lever to move it to position to disengage said sear, and spring means to urge said sear toward striker-engaging position.

5. A firearm comprising a frame, a striker reciprocably mounted thereon, a sear pivotally mounted on the frame and adapted to engage the striker to hold it in cocked position, a scar lever pivotally mounted on the frame on a vertical axis for lateral swinging movement, said lever being disposed forwardly of the sear and having a part adjacent the rear end thereof adapted to lie below a part of the sear and hold it in striker-engaging position, triggeractuated means to move said lever about its pivot to move the rear end thereof to position to disengage the sear and permit movement of the sear to position to release the striker, and spring means urging said sear toward said last-named position.

6. A firearm comprising a frame, a striker reciprocably mounted thereon, a sear pivotally mounted on the frame and adapted to engage the striker to hold it in cocked position, a sear lever pivotally mounted on the frame on a vertical axis for lateral swinging movement, said lever having a part adapted to engage the sear to hold it in striker-engaging position, a trigger-actuated means engaging said lever to move it to position to disengage said sear, said last-named means comprising a sear bar movable longitudinally of the frame having one end engaging the sear lever, and a trigger pivoted to the frame and connected to the sear bar.

7. A firearm comprising a frame, a striker reciprocably mounted thereon, a sear pivotally mounted on the frame and adapted to engage the striker to hold it in cocked position, a sear lever pivotally mounted on the frame on a vertical axis for lateral swinging movement, said lever having a part adapted to engage the sear to hold it in striker-engaging position, said sear lever being of bellcrank shape with its forward portion extending transversely of the frame, and trigger-actuated means to engage said forward portion of the lever to move it to sear-releasing position.

8. A firearm comprising a frame, a striker reciprocably mounted thereon, a sear pivotally mounted on the frame and adapted to engage the striker to hold it in cocked position, a sear lever pivotally mounted on the frame on a vertical axis for lateral swinging movement, said lever having a part adapted to engage the sear to hold it in striker-engaging position, said sear lever being of bell-crank shape with its forward portion extending transversely of the frame, trigger-actuated means to engage said forward portion of the lever to move it to sear-releasing position, and adjustable stop means engaging said sear-release lever to limit its engagement with the sear.

9. A firearm comprising a frame, a striker reciprocably mounted thereon, a sear pivotally mounted on the frame and adapted to engage the striker to hold it in cocked position, a sear lever pivotally mounted on the frame on a vertical axis for lateral swinging movement, said lever having a part adapted to engage the sear to hold it in striker-engaging position, a trigger-actuated means engaging said lever to move it to position to disengage said sear, spring means urging said sear lever toward searengaging position, and means to adjust the tension of said spring.

10. A firearm comprising a frame, a striker reciprocably mounted thereon, a sear pivotally mounted on the frame and adapted to engage the striker to hold it in cocked position, a scar lever pivotally mounted on the frame on a vertical axis for lateral swinging movement, said lever being of bell-crank shape and having one arm extending longitudinally of the frame with its rear end 7 engaging the sear to hold it in striker-engaging position, the second arm of said lever extending transversely of the frame, a longitudinally movable sear bar having a rear end portion engaged with the second arm of the sear lever, and a trigger connected to the forward end of said sear bar adapted to move it longitudinally of the frame to move said sear lever to position to disengage the sear.

References Cited in the file of this patent UNITED STATES PATENTS 

